Install os-release(5) content to /usr/lib and have /etc/os-release be a symlink
    
    When trying to use CentOS to build "stateless" systems or building nspawn
    containers, the presence of os-release(5) data in /usr/lib/os-release is
    expected. Not having this file causes problems for tools that expect
    the data to be in /usr/lib/os-release and would regenerate the symlink
    in /etc/os-release.
    
    Reference: https://bugzilla.redhat.com/1766754
    
    Signed-off-by: Neal Gompa <ngompa@centosproject.org>